1. Field of the Invention
The present invention relates to metal working machinery and more particularly to machines for finishing the ends of metal tubing to precise dimensions and with any desired internal and/or external beveling. The preferred embodiment of the invention is a machine designed for quantity production of finished tubing, but many of its features will be found adaptable to portable tube finishing machines.
2. The Prior Art
Machines designed for the purposes of the present invention have employed various kinds of devices for holding a workpiece in a fixed relation with respect to metal working tools for shaping and finishing tube ends. The work holding devices employed have included both conventional chucks and other arrangements for gripping the exterior surfaces of workpieces. Examples of such devices are found in the Strout U.S. Pat. No. 3,228,268 and Saine U.S. Pat. No. 4,319,503.
When it is required in tube finishing that close dimensional tolerances be maintained, and especially where rates of production are important, such devices have not proved satisfactory, principally because of the difficulty of closing such chucks or the like without allowing some movement of the workpiece or, in the case of relatively thin-walled tubing, distorting the stock out of round.